Rotary pivoted hammer



Nov. 17 1925" j'i'y- H. M. PLAISTEIJ ROTARY PIVOTIED Filed'Feb. 2

Patented Nov. 17, 1925.

UNITED STATES HAROLD M. PLAISTED, OF ST. LOUIS, MISSOURL.

ROTARY rIvoTEn HAMMER.

Application filed February 23, 1923. Serial No. 620,676.

To all whom, it may OOH-667%.

Be it known that I, HAROLD M. PLAISTED, a citizen of the United States,residing at St. Louis, State of Missouri, have invented certain new anduseful Improvements in Rotary PivotedHammers, of which the following isa specification.

This invention. relates to certain new and useful improvements in rotarypivoted ha1n mers for crushers and pulverizers for use with coal, shale,grain or other material, the peculiarities of which will be hereinafterfully described and claimed.

The main object of my invention is to provide a rotary pivoted hammerwith an adjustable cutter block adapted to present eight cutting edgesin succession as the operative edge and fully protect from wear alledges exceptthe one in operative position; secondly, to form the cuttingedges on said block so as to'maintain a sharp cutting edge while beingworn down; and thirdly, to mount such a block detachably, yet securelyin the head of the hammer.

In the accompanying drawing on which like reference numerals indicatecorresponding parts, Fig. 1, represents a front View of a hammerexemplifying my invention; Fig. 2, a side view of the same; Fig. 3, arear view; Fig. 4, a detail front view of the 'cutterblock; and Fig. 5,a section on the line 5-5 of Fig. 4:.

1 designates the shank of a rotary pivoted hammer having an eye, 2 atone end for pivotal mounting. as usual, and having a head 3 considerablythicker than the shank l as shown in Figs. 1 and 3. In this head isformed a recess 4 dividing the head into two aws 6 and 7,the formerbeing shorter than the rear jaw 7. In this recess is mounted a cutterblock, 23, preferably cruciform as viewed from the side, Fig. 2, andconsisting of four radiating arms 8, 9, 10,

and 11 formed by cutting away portions of the block as indicated in Fig.5. The sides of said arms are preferably curved so as to make acuteangles with the ends of the arms asshown in Figs. 2 and 5. The sides ofthe arms may be otherwise than curved if desired, but the preferred formallows of still presenting a sharp cutting edge as the operative edge isworn down in the reduction of material. The sides of the arm are adaptedto constitute bearing surfaces to support the block in the recess, andsaid recess has matching bearing portions preferably three, designated12, 13 and 14, adapted to beengaged by a corresponding number of theeight bearing surfaces at the side of said arms, whatever the adjustmentof the block by rotating and reversing the same. The non-bearingportions of the recess allow play for readily assembling'the block andhead.

The front jaw is shorter than the rear jaw so as to expose the outercutting edge 22 of the block and adjacent throat, to the material beingreduced, and still protect the next forward cutting edge of the blockfrom wear by the material. The rear jaw backs up the outer cutting edgein operation, and also protects the next adjacent rear edge of the blockwith whichit is practically even or flush as shown.

Means for securing the block detachably in the recess are provided,preferably a bolt 15 mounted in the head 3 inclined to the radial axis Xthrough the pivot and center of gravity of the hammer, and extendingthrough the block diagonally by means of through passages 16 and 17 5,that cross each other at the center'of the'block, and are enlarged tosink the head of the bolt as shown in Fig. 2. A nut 18 on the threadedend of the bolt, or other fastening means for the bolt, allows ofdrawing the cutter block down against the bearing portions of the recessso as to engage the adj acent bearing surfaces of the block. A springwasher 19 of leather or other suitable material, is compressed by thenut 18 against a boss 20 at the back of the head, and a cotter 21prevents its turning off. The bolt preferably passes through the bearingportion 13 and the bearingsurface of the arm engaged thereby, and isintermediate of the bearing portions 12 and 14 so that the block is heldfirmly yet detachably.

The cutting edges of the block are equidistant from the center asindicated in Fig. 5, and the radial axis Y of the recess is inclinedbackward from the direction of rotation so as to bring the outer frontedge 22 further from the central axis of the pivot than the adjacentrear edge of the same arm. This edge 22 is the operative edge in theadjustment of the block shown, and all the other cutting edges arehidden by the jaws 7 and Sand the recess, so that they are protectedfrom wear. Each edge however may be readily adjusted to the position ofthe edge 22 and become in succession the operative edge, until all theedges are worn down. The bearing portions of the recess engaging theside bearing surfaces of the arms bring each cutting edge'in successionto the same operative position and the fastening means, such as the boltpassing through the cross passages 16 and 17, hold the cutter blocksecurely yet detarhaoly in the head' This hammer is pivotally mounted inmultiple in any suitable manner to form a rotor in a casing, such as onrods in perforated discs mounted on a rotor shaft as shown in my priorPatent No. 1,113,611, dated April 25th, 1922. i

I claim:

1. A rotary pivoted han'imei' comprising a shank adapted for pivotalmounting and having a solid head with a recess having three bearingportions, a cutter block ad justably mounted in said recess and havingeight operative edges,-said head being adapted to protect from wear alledges cw cept the one in operative position, and said block having eightbearing surfaces, three of which engage said bearing portions of therecess in each adjustment of the block,- and means detachably securingsaid block in said recess.

2. A rotary pivoted hammer comprising a shank adapted for pivotalmounting and having a solid head with a recess ha ing three bearingportions, a cutter block adjustably mounted in said recess and havingeight operative edges,said head being adapted to protect from wear alledges e2:- cept the one in operative position, and said blockhaving'eight bearing surfaces, three of which engage said bearingportions of the recess in each adjustment of the block, a bolt passingthrough said block and head at one bearing portion of the recessintermediate of the other two, and fastening means for said bolt.

3. A rotary pivoted hammer comprising a shank adapted for pivotalmounting and having a solid head with a recess having bearing portions,a cutter block adjustably mounted in-said recess and having bearingsurfaces successively matching said bearing portions of the reeess,-saidblock having reentrant cutaway portions forming eight edges adapted toform successively the operative edge while the others are hidden in saidrecess, and having through passages crossing each other and connectingopposite cutaway portions, and fastening means adapted to be mounted insaid head and one of the through passages of said block successively andintermediate of the bearing portions of the recess and theircorresponding bearing surfaces of the block.

t. A rotary pivoted hammer comprising a shank adapted for pivotalmounting and having a solid head with a recess form ing a front jaw anda longer rear jaw, a cruciform cutter block with multiple cutting edgesadjustably mounted in said recess and having only its front operativeedge ex posed by the front jaw and located further from the pivot thantheother cutting edges, and means adjustably securing said block in saidrecess.

5. A rotary pivoted hammer comprising a head having a shank adapted forpivotal mounting a cruciform cutter block mounted in said head andhaving eight cutting edges equidistant from the center of the block, ahead on said hammer having a recess in one side receiving said blockmounted therein and covering all but the outer front one of said edgesthe head being provided with a shank adapted for pivotal mounting, andthe radial axis of the recess being inclined backward so that theexposed operative edge is at a greater distance from the pivot than theadjacent rear edge of the block.

6. A rotary pivoted hammer comprising a head having a shank adapted forpivotal mounting, a cruciform cutter block mounted in said head andhaving eight cutting edges equidistant from the central axis of theblock, the side surfaces of the arms of the cross being curved andforming an acute angle with the end surfaces of the arms making sharpcutting edges, and adapted to be fastened in said hammer.

7. A rotary pivoted hammer comprising a head having a shank adapted forpivotal mounting, a cruciform cutter block mounted in said head andprovided with eight cutting edges,the central portions of the blockhaving two through passages crossing each other in the center andconnecting opposite cutaway portions, substantially as shown and for thepurpose set forth.

8. A rotary pivoted hammer comprising a shank adaptedfor pivotalmounting at one end and provided with a solid head having a recess atits outer end and on one side dividing it into outwardly projectingjaws-the front being shorter than the rear jaw,-a cutter block mountedin said recess and exposing one cutting edge beyond the front jaw, andmeans detachably securing said block in the head.

In testimony whereof I have affixed my signature.

HAROLD M. PLAISTED.

